diff --git a/src/main.rs b/src/main.rs
index 129f0f3..fc9db41 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,26 +1,50 @@
-use std::cmp::Ordering;
-
 struct Solution;
 mod arr;
 
 impl Solution {
-    pub fn sort_by_bits(arr: Vec<i32>) -> Vec<i32> {
-        let mut arr= arr.iter().map(|&x| ->(i32,i32){
-            (x,x.count_ones() as i32)
-        }).collect::<Vec<(i32,i32)>>();
-        arr.sort_unstable_by(|a,b|-> Ordering {
-            let res = a.1.cmp(&b.1);
-            match res {
-                Ordering::Equal => a.0.cmp(&b.0),
-                _ => res,
+    pub fn min_swaps(grid: Vec<Vec<i32>>) -> i32 {
+        fn count_tail_zero(arr: &Vec<i32>) -> i32 {
+            let mut cnt = 0;
+            for i in (0..arr.len()).rev() {
+                if arr[i] == 0 {
+                    cnt += 1;
+                } else {
+                    return cnt;
+                }
             }
-        });
-        arr.iter().map(|&(x,_)| x).collect()
+            cnt
+        }
+        let mut arr = Vec::<i32>::with_capacity(grid.len());
+        for i in 0..grid[0].len() {
+            arr.push(count_tail_zero(&grid[i]))
+        }
+        let mut cnt = 0;
+        for i in (0..grid.len()).rev() {
+            let mut index = 0;
+            let mut cant = true;
+            for j in 0..arr.len() {
+                if arr[j] == -1 {
+                    continue;
+                }
+                if arr[j] >= i as i32 {
+                    arr[j] = -1;
+                    cnt += index;
+                    cant = false;
+                    break;
+                }
+                index += 1;
+            }
+            if cant{
+                return -1;
+            }
+        }
+        cnt
     }
 }
+
 fn main() {
-    let result = Solution::sort_by_bits(
-         vec![0,1,2,3,4,5,6,7,8]
-    );
+    let result = Solution::min_swaps(arr::make_matrix(
+        "[[0,0,1],[1,1,0],[1,0,0]]",
+    ));
     println!("{:?}", result);
-}
\ No newline at end of file
+}